At the present time in the development of mobile systems, locomotion is primarily achieved through the use of wheels or tracks. Wheeled vehicles are in an advanced state of development for locomotion on flat prepared surfaces. However, mechanical means for off road locomotion have not been perfected to a comparable degree. Locomotion based on the use of wheels is most effective on prepared surfaces and degrades rapidly when soft soil or rough uneven terrain is encountered.
The use of tracked vehicles partially solves this problem for outdoor locomotion, but to a lesser degree than it is generally assumed. Specifically, only about fifty percent of the land surface is acceptable to track vehicles, while nearly all the land surface of the earth is freely traversed by large animals. Moreover, on terrain on which track vehicles can be used, animals are typically capable of considerably more speed at a greatly reduced energy cost. It has been determined that the reason for the superior performance of animals in off road locomotion lies in the adaptive nature of leg locomotion. One leading expert in the field has observed that while the number of experimental leg vehicles have demonstrated terrain adaptability and mobility comparable to animals of similar size, the energy efficience of these vehicles is very low, even in comparison with tracked vehicles, and at least two orders of magnitude inferior to the performance of animals in comparable terrain.
Various types of vehicles with artificial legs have been proposed for off road vehicles. All such legged vehicles thus far known have not been known to be energy efficient. The legged vehicles generally comprise a vehicle body with a plurality of legs in which some are lifted during a step or sequence of motion to be advanced and support the vehicle or vehicle platform as it is advanced by the legs contacting the ground.
It is important that the movement and motion of the legs, impart only what is referred to as "straight line" motion to the vehicle body. Otherwise, the vehicle will be subjected to vertical motion.
Accordingly, the present invention provides a new and improved walking leg mechanism for a walking vehicle which provides for straight line motion of the vehicle, while being very energy efficient.